Apparatus for reducing compounds and producing carbids.



PATENTED JULY 24, 1906.

B. P. PRICE. OR REDUCING COMPOUNDS AND PRODUCING CARBIDS. APPLIOATION FILED ABBA, 1904. RENEWED JAN. 18. 190s.

APPARATUS 2 SHEETS-SHEBT 1.

zall a'l fllfel ll al Bel armor- 7 VLULesses ZZZ PATENTED JULY 24, 1906.

E. 1?. PRICE. APPARATUS FOR REDUCING COMPOUNDS AND PRODUCING GARBIDS.

APPLICATION FILED APRA, 1904. RENEWED JAN. 18, 1906.

2 SHEETS-SHEET 2 UNITED srnrns n rnnr carton.

EDGAR F. .PRIOE, OF NIAGARA FALLS, NEW YORK, ASSIGNOR TO UNION CARBIDE COMPANKOF NIAGARA FALLS, NEW YORK, A CORPORATION OF VIRGINIA:

APPARATUS FOR REDUCING COMPOUNDS AND PRODUCING CARBIDS.

Specification of Letters Patent.

ratented July 24, 1906.

To all whom it may concern:

Be it known that I, EDGAR F. Pinon, a citizen of the United States, residing at Niagara Falls, in the county of Niagara and State of New York, have invented certain new and useful Improvements inApparatus for Beducing Compounds and Producing Oarbids, of which the following is a specification.

This invention especially relates to apparatus for the production of calcium carbid by the use of an electric resistance-furnace.

The apparatus comprises a preheating chamber in which the charge, usually a mixture of finely-divided lime and coke,,is showered downward through a hot atmosphere and an electric. furnace in which the pre heated material is collected into a body and heated to'the required temperature either by passing an electric current through the heated charge or themolten products thereof, acting as aresistance-conductor, or through a separate resistance-conductor in proximity to the charge. The preheating is preferably efiected by Withdrawing the waste carbon monoxid from the electric furnace and burning it in the preheating-chamber. Other fuel, such as natural gas or oil, may be employed as a substitute for or'adjunct to the carbon monoxid.v

. For the purpose of illustration I have shown apparatus employing two different typesof electric by me, in both of which the density of the electric current increases through the resistance-conductor from the receiving toward the discharge end of the furnace, a construction which enables the heat to be increased along the path-of the electric current to a point Where the carbid becomes molten and may be tapped from the furnace.

Referring to the accompanying drawings, Figure 1 is a vertical axial section of a furnace in which the working chamber decreases in cross-section from the receiving to thedischarge end, and Fig. 2 is a vertical axial section of a furnace in which superposed electric currents pass through a resistance-conductor distinct from and surrounding the charge.

The furnace shown in Fig. 1 is an annular stack having a body 1, of refractory non-conducting material, such as magnesia firebrick, inclosed by a' casing 2 of iron. 7 The major .portionof the body is a downwardlyfurnaces heretofore devised converging bosh which is surrounded by a water-jacket-3. The hearth 4 of the furnace consists of a solid mass of carbon set in a an iron casing 5, which is insulated from the casingZ by a refractory layer 6. A tap hole 7 for the molten products extends through the hearth. One terminal 8 of the source of electric current is secured to the hearth-casing 5, the hearth thus serving as one electrode. A number of radial electrodes 9 of the same polarity, here shown as cylindrical carbon rods, pass horizontally through the side walls of the furnacenear its top. Supported upon and openin unto the upper end of the furnace is the pre eating-chamber 10, consisting of a shell 11, of iron, with a lining 12, of refractory material, such as magnesia or SilOXlCOIl fire-brick. Upon the upper end of the preheating-chamber is a hopper 13, the lower end of which is closed by a perfo rated plate 14. Another perforated plate 15 is arranged to reciprocateupon the plate 1 1, being driven by a crank andpitman. Pipes 16 for Withdrawing the carbon monoxid from the electric furnace extend upward through its top and are connected at their upper ends to burners 17 with air-blast pipes l8,:which enter openings in the sides of the preheatingchamber. 19, supplied by gaseous or liquid fuel from some external source, may also be employed. The products of combustion escape from the upper end of the chamber through a flue 20 One or more auxiliary burners and may be used in a hot-blast stove to heat the air for the burners.

finely-ground coke and lime in the hopper 13 is delivered by the perforated plates in the form of a shower, which falls freely downward through the preheating-chamber against the hot products of combustion rising from the burners, and thence into the electric furnace, where it collects as a body. When the preheated charge in the furnace accumulates to a height sufiicient to surround the upper electrodes 9, an electric current is passed be.- tween these electrodes and the carbon hearth through the charge, acting as a resistanceconductor. The preheatedmaterial is thereby readily raised to the temperature requisite for the production of calcium -carbid, and the carbon monoxid evolved by the reaction is thereafter employed to preheat the the electric current increases along the path of the current throughthe charge, thereby increasing the amount of heatevolved from its upper toward its lower portion. The temperature of the charge and of the calciumcarbid product thus rises toward the lower part of the furnace and may be kept at a point sufficiently high to maintain a con siderable pool of the molten carbid in the furnace, this pool then serving as a resistanceconduotor as well as the char e. The molten carbid is removed through t e tap-hole 7 as desired.

The furnace shown in Fig. 2 comprises a vertical stack 21, of refractory non-conducting material, such as magnesia fire-brick, within which is a continuous tubular lining 22, of refractory conducting material, such as carbon. The hearth 23 of the furnace is also of refractory conducting material, such as carbon, and has a tap-hole 24. A plurality of metal rings 25, shown as two in number, surround the carbon lining 22 and are con nected to one terminal or several terminals of like sign of the source or sources of'electric current. Each of these metal rings preferably has a central passage 26 for water or other coolin medium. The other terminal or termina s 27 of the source or sources of electric current are connected to an iron plate 28, which underlies and makes good electrical contact with the carbon hearth 23. The metal rings 25 are built into the brick shell of the furnace and are so arranged and spaced upon the car- -bon lining 22 that the current flowing through this linin acting as a resistance-conductor from the ower ring 25 to' the hearth 23 is superposed upon the current flowing from the upper ring 25 through the resistanceconductor to the hearth. The density of the total current flowing throu h the resistance-com ductor is thus increase by one or more steps,

depending on the number of rings from the upper to the lower end of the conductor, so that it is heated uniformly. The preheating- Y chamber 10 shown in connection with this to raise it to the temperature required for t e second furnace is heretofore describe Similar parts have been designated by the same numerals, and further description is unnecessary.

In operating the furnace shown in Fig. 2

, the charge is showered downward throughthe roduction of calcium carbid. The current owing between the lower ring-terminal 25 and the hearth heats the lower part of theresistance-conductor to a. temperature suffirecisely similar to that,

The resistance-conductor is then seams cient to bring the carbid into a molten condition and'enable it to be removed through the tap-hole 24. y

It will be seen that in the operation of each of these furnaces the charge of finely-d vided lime and carbon or other material is preheated by showering it through a hot atmosphere and that the particles of the charge are then collected into a body which is further heated to the required temperature by an electric current passing through a resistance-conductor, whether this conductor be the charge, the molten product thereof, or a separate conductor in proximity to the charge.

I am aware that United States Patent No. 557,057, granted March 24, 1896, to Edward N. Dickerson, discloses an apparatus for producing calcium carbid in which the charge is fed into an electric furnace and the carbon monoxid is utilized to heat the mixture as it is being fed into the furnace. While the present apparatus is generically included within the terms of this patent, it specifically differs therefrom, in that the charge is preheated by being showered downward through the burn ing carbon monoxid instead-of being packedin a muffle which is heated externally.

I am also aware that United States Pat 5m- No. 656,599, granted August 21, 1900,5129- Reuben Doolittle, describes an apparatus for" making carbids in which the charge falls downward through a vertical shaft between burners and then between a series of electrodes. In this case, however, a large number of electrodes is necessary to heat the charge to the requisite hightomperature on ac count of theshort period of time during-which it is exposed to the action of each electric are as it falls through it. In my apparatus the preheated particles of the charge are collected into a body and are then efiiciently heated by the action of an electric current, the hot charge and its molten product preferably bein em loyed as a resistanceconductor.

hi e the apparatus has been specifically described in connection with the production of calcium carbid', it is obvious that it ma be employed for various chemical and meta lurgical operations in which finely-divided material must be heated to a high temperature.

The term relatively large body occurlates in the region of the smelting zone, so

that it can be subjected to the electric heating for a relatively considerable period. By collecting such considerable amount of material and surrounding the smelting zone therewith the heat imparted to the showered charge is retained in the, material, and the body of material surrounding the smelting zone serves to retain the heat develo ed. by

ithe electric current. The term divi ed mavmaterial mosphere, an electric resistance-furnace con-' terials is-intended to mean round, pulverized, comminuted, and granui ar materials.

claim- 1. An apparatus for smelting divided ma.- terials, comprising means for preheating the material by showering it through a hot .at, mosphere, an electric resistance-furnace, and means for charging a body of the preheated material into said furnace, as set forth.

2. An apparatus for smelting divided materials, comprising means for preheating the by showering it through a hot at structed to gradually raise the preheated material to the required temperature, and means for charging a body of the preheated material into said furnace, as set forth.

3. An apparatus for smelting divided materials, comprising means for preheating the material by showering it through a hot atmosphere, an electric resistance-furnace con structed to gradually raise the preheated material to the required temperature and to bring the product into a molten condition, said furnace having a tap-hole, and means for charging a body of the preheated material into said furnace, as set forth.

4. An apparatus for smelting divided materials, comprising means for preheating the material by showering it through a hot atmosphere, an electric furnace having a resist ance conductor and means for passing through said conductor an electric current of increasing density, and means for charging a body of the preheated material into said furnace, as set forth.

5. 'An apparatus for smelting divided materials, comprising means for preheating the material by showering it through a hot atmosphere, an electrlc furnace having a resistance-conductor, means "for passing through said conductor an electric current of increas-v ing density and atap-hole adjacent to the region of maximum current density, and means for charging a body of the preheated material into said furnace, as set forth.

6. An apparatus for smelting divided ma terials, comprising means for preheating the material by showering it through a hot atmosphere, an electric resistance-furnace, means for charging a body ofthe preheated material into said furnace,- and means for burning the waste gases from the electric furnace to furnish the preheating atmosphere, as set forth.

7. An apparatus for smelting divided materials, I comprising means for preheating the mosphere,

. mosphere, means for collecting the showered material by showering it through a hot atmosphere, means for collecting the showered particles into a relatively large body, means for electrically heating said body to the required temperature and bringing the roduct into a moltencondition, and a tapiole for themolten product, as set forth.

\8. An apparatus for smelting divided materials, comprising means for preheating the material by showering it through a hot atmosphere, means for collecting the showered particles into a relatively lar e body, and means for gradually heating said body to the required temperature by an electric current of increasing density, as set forth.

9. An apparatus for smelting divided materials, comprising means for preheating the I material by showering it through a hot atmeans for collecting the showered particles into a relatively large body. means for gradually heating said body tothe required temperature and for bringing the product-into a molten condition by an eleca. tric current of increasing density, and a ta hole for the molten product adjacent to t e region of maximum forth.

10. An apparatus for smelting divided m'a- 8 5 terials, comprising means for preheating the' material by showering it through a hot atmosphere, means for collecting the showered particles into a relatively large body, means for electrically heating said body to the required temperature and bringingthe product into a molten condition, atap-hole for the molten product, and means for burningthe waste gases to furnish the preheating atmosphere, asset forth.

I1. An apparatus for smelting divided materials, comprising means for preheating the material by showering it through a hot atcurrent density, as set partlcles into a relatively large body, means for gradually heating said body to the -re-' quired temperature and for bringing the product into a molten condition by an ejectric current of increasing density, a tap-hole for the molten product adjacent to the region of maximum current density, and means for burning the waste gases to furnish the'pre-' heating atmosphere, as set forth.

In testimony whereof I affix my signature in presence of two witnesses. 1

' EDGAR F. PRICE.

Witnesses:

CHAS. E. BrLLrNes B. OCoNNoR.

IOO 

